78387520 has 56 divisors (see below), whose sum is σ = 187415424. Its totient is φ = 31228416.

The previous prime is 78387481. The next prime is 78387523. The reversal of 78387520 is 2578387.

It is a super-2 number, since 2×78387520² = 12289206583500800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78387523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155589 + ... + 156091.

It is an arithmetic number, because the mean of its divisors is an integer number (3346704).

Almost surely, 2^78387520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78387520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93707712).

78387520 is an abundant number, since it is smaller than the sum of its proper divisors (109027904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78387520 is a wasteful number, since it uses less digits than its factorization.

78387520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007 (or 997 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 78387520 is about 8853.6726842593. The cubic root of 78387520 is about 427.9722810825.

The spelling of 78387520 in words is "seventy-eight million, three hundred eighty-seven thousand, five hundred twenty".